River Crossing Puzzle

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Get everyone across the river by boat.

Only the farmer rows, with one thing at a time. Without him, the wolf eats the goat and the goat eats the cabbage.

How to play the river crossing puzzle

Move everyone from the near bank (bottom) to the far bank (top) by boat, without ever breaking the puzzle’s rules. The trick is choosing who goes together, and in what order.
Tap someone on the bank to put them in the boat, and tap them in the boat to send them back ashore. Then tap “Cross” (or the boat itself) to row over. Everyone gets out on arrival.
The boat can’t move on its own: someone has to row it, both ways. When only some characters can row, they wear an oar badge.
A move that breaks a rule isn’t allowed. The reason appears above the river, and whoever is in trouble gets a red ring.
Each crossing in either direction counts as one trip. Solve a puzzle in the fewest trips to earn a ★ in the puzzle list. Timed puzzles are solved when everyone is across within the time limit.
Stuck? “Hint” shows who to send next, and “Solve” plays the shortest solution from where you are (solves with the answer shown aren’t recorded — no ✓ or ★). Your progress is saved, so you can close the page and come back.

The 11 puzzles and their rules

Puzzle	Rules	Best
Wolf, goat and cabbage	Only the farmer rows, taking one thing at a time. Without the farmer, the wolf eats the goat and the goat eats the cabbage	7 trips
Two adults, two children	The boat holds one adult or two children. Anyone can row	9 trips
4 people in 17 minutes	They take 1, 2, 5 and 10 minutes. Two at a time, at the slower one’s pace	17 min
3 sheep and 3 wolves	The boat holds 2. Wherever there are sheep, wolves must not outnumber them, on the banks or in the boat	11 trips
3 parents, 3 children	The boat holds 2. A child can’t be with another parent unless their own parent is there	11 trips
5 people in 29 minutes	They take 1, 3, 6, 8 and 12 minutes. Same rules as the 17-minute puzzle	29 min
Only two can row	3 sheep and 3 wolves, but only one sheep and one wolf can row	13 trips
4 sheep and 4 wolves	The boat holds 3. Same rules as 3 and 3	9 trips
4 parents, 4 children	The boat holds 3. Same rules as 3 pairs	9 trips
5 sheep and 5 wolves	The boat holds 3	11 trips
Family (police and thief)	Dad, Mom, two sons, two daughters, a police officer and a thief. The boat holds 2, and only Dad, Mom and the officer can row. Dad can’t be with a daughter without Mom, Mom can’t be with a son without Dad, and the thief can’t be with any family member without the officer	17 trips

How to solve river crossing puzzles

Wolf, goat and cabbage

The goat is the troublemaker: it can be left with neither the wolf nor the cabbage. Take the goat first, and when you reach the far bank the second time, bring the goat back with you. Realizing you may carry something back is the whole trick.

Answer (7 trips)

Farmer takes the goat across
Farmer returns alone
Farmer takes the wolf across
Farmer brings the goat back
Farmer takes the cabbage across
Farmer returns alone
Farmer takes the goat across

You can swap the wolf (step 3) and the cabbage (step 5).

Bridge and torch: 4 people in 17 minutes

Send the two slowest people (5 and 10 minutes) together, so you only pay for the slowest one once. To make that work, first get the two fastest people across so they can bring the boat back.

Answer (17 minutes)

1 and 2 cross (2 min)
1 returns (3 min)
5 and 10 cross (13 min)
2 returns (15 min)
1 and 2 cross (17 min)

Missionaries and cannibals (sheep and wolves)

On any bank with at least one sheep, keep the wolves no more than the sheep. A bank with no sheep can hold any number of wolves, so start by gathering wolves on the far bank while you ferry the sheep.

Answer (3 and 3, 11 trips)

A sheep and a wolf cross
The sheep returns
Two wolves cross
A wolf returns
Two sheep cross
A sheep and a wolf return
Two sheep cross
A wolf returns
Two wolves cross
A sheep returns
A sheep and a wolf cross

Family river crossing (police officer and thief)

The thief either travels with the officer or waits alone on a bank with no family. Move people in safe pairs such as Dad with a son or Mom with a daughter, and check every return trip against the rules.

Answer (17 trips)

Officer and thief cross
Officer returns
Officer and a son cross
Officer and thief return
Dad and a son cross
Dad returns
Dad and Mom cross
Mom returns
Officer and thief cross
Dad returns
Dad and Mom cross
Mom returns
Mom and a daughter cross
Officer and thief return
Officer and a daughter cross
Officer returns
Officer and thief cross

Where river crossing puzzles come from

River crossing puzzles are very old. Propositiones ad Acuendos Juvenes (Problems to Sharpen the Young), a collection attributed to Alcuin from around 800, already includes the wolf, goat and cabbage problem and a problem in which three brothers and their sisters cross in a small boat, a form better known as the jealous husbands problem. The “3 parents, 3 children” puzzle here follows that pattern.

The wolf, goat and cabbage riddle is also told with a fox, a chicken and corn (or beans). The sheep and wolves puzzles follow the classic missionaries and cannibals problem, with the same rule that one group must never be outnumbered. The timed puzzles are the boat version of the bridge and torch problem.

FAQ

How is the fewest number of trips worked out?

The game checks every possible arrangement of who is where and finds the shortest way to get everyone across. A crossing in either direction counts as one trip. “Hint” and “Solve” use the shortest solution from where you are now.

Is it the same as the fox, chicken and corn riddle?

Yes. The fox is the wolf, the chicken is the goat and the corn is the cabbage. The answer is the same 7 trips: the key is bringing the chicken back.

Can the boat cross empty?

No. Someone has to row, even on the way back. That is what makes these puzzles tricky.